Rogue extensions that hijack Chrome & Firefox are near impossible to remove

January 20, 2018 – 11:05 AM

As discovered by Malwarebytes researcher Pieter Arntz, a new pair of extensions plaguing Google’s Chrome and Mozilla’s Firefox can hijack the browsers in order to push technical support scams at you and potentially even spy on your browsing activities.

Called “Tiempo en colombia en vivo” on the Chrome Web Store, the rogue extension can be installed on a machine when the user visits certain sites; trying to leave a malicious site results in an infinite loop of dialog boxes cautioning the user that they can’t leave the page until they install the extension. If they try to leave still, and choose the option to “Prevent this page from creating additional dialogs,” the tab will go into full screen mode and offer the ‘Add extension’ dialog popup that shows up when installing a Chrome extension.

If the user ends up installing the extension, it will proceed by hijacking their browser searches and redirect them to certain pages or YouTube videos in order to increase their views.

Interestingly, the extension is designed to also make its removal a difficult procedure; the first measure taken to ensure this is to redirect users from the ‘chrome://extensions/’ page where they could manage and delete the extension to ‘chrome://apps/?r=extensions’, which simply lists the various Chrome apps and extensions that they have installed.

With the normal path to deleting an extension now unavailable, most casual users will likely not be able to remove the extension. In his efforts, Arntz even tried more advanced methods such as disabling JavaScript, starting Chrome with all extensions disabled, and renaming the file path for where extensions are saved, but to no avail.

The only means of successfully removing the extension at this point is, per Artnz, to install Malwarebytes and let the anti-malware program do it for you. Alternatively, you may also try and manually browse to the extension’s folder and rename ‘1499654451774.js’, which is the JavaScript file the extension relies on. You can then restart Chrome and will be able to access the browser’s extension settings as normal, with the offending extension shown as being corrupted – and unable to work its nefarious magic as it can’t find the files it’s looking for. You can then proceed to delete it as you normally would.


A flaw in Intel AMT can leave your laptop exposed to attackers

January 12, 2018 – 8:44 PM

Following on the heels of the revelations of the Meltdown and Spectre vulnerabilities plaguing decades of Intel’s processors, a new flaw in the Active Management Technology (AMT) has left Intel in even more hot water among the cybersecurity community.

The new flaw targets laptops, especially those powered by Intel’s enterprise-focused vPro processors, and exploits the remote access monitoring and maintenance tools provided by AMT to gain total control over the machine. Relatively easy to implement, the attack is also not impeded in any way by BIOS or BitLocker passwords, TPM pins, or login credentials.

In order to carry out the attack, an individual would need physical access to the machine. The way it works is by rebooting the machine and entering the boot menu. While you would normally need the BIOS password in order to perform any hijinks at this point, using Intel’s Managment Engine BIOS Extension (MEBx) can allow an attacker to login in with a simple ‘admin’ login that is the default.

The attacker can then proceed by, “changing the default password, enabling remote access and setting AMT’s user opt-in to ‘None'” to effectively compromise the machine, according to F-Security researcher Harry Sintonen. He continues, “Now the attacker can gain access to the system remotely, as long as they’re able to insert themselves onto the same network segment with the victim (enabling wireless access requires a few extra steps).”


Every modern processor has unfixable security flaws

January 3, 2018 – 7:32 PM

Windows, Linux, and macOS have all received security patches that significantly alter how the operating systems handle virtual memory in order to protect against a hitherto undisclosed flaw. This is more than a little notable; it’s been clear that Microsoft and the Linux kernel developers have been informed of some non-public security issue and have been rushing to fix it. But nobody knew quite what the problem was, leading to lots of speculation and experimentation based on pre-releases of the patches.

Now we know what the flaw is. And it’s not great news, because there are in fact two related families of flaws with similar impact, and only one of them has any easy fix.

The flaws have been named Meltdown and Spectre. Meltdown was independently discovered by three groups—researchers from the Technical University of Graz in Austria, German security firm Cerberus Security, and Google’s Project Zero. Spectre was discovered independently by Project Zero and independent researcher Paul Kocher.

At their heart, both attacks takes advantage of the fact that processors execute instructions speculatively. All modern processors perform speculative execution to a greater or lesser extent; they’ll assume that, for example, a given condition will be true and execute instructions accordingly. If it later turns out that the condition was false, the speculatively executed instructions are discarded as if they had no effect.

However, while the discarded effects of this speculative execution don’t alter the outcome of a program, they do make changes to the lowest level architectural features of the processors. For example, speculative execution can load data into cache even if it turns out that the data should never have been loaded in the first place. The presence of the data in the cache can then be detected, because accessing it will be a little bit quicker than if it weren’t cached. Other data structures in the processor, such as the branch predictor, can also be probed and have their performance measured, which can similarly be used to reveal sensitive information.


Extended Validation Is Broken

December 13, 2017 – 5:38 AM

Extended validation (“EV”) certificates are a unique type of certificate issued by certificate authorities after more extensive validation of the entity requesting the certificate. In exchange for this more rigorous vetting, browsers show a special indicator like a green bar containing the company name, or in the case of Safari completely replace the URL with the company name.

Generally, this process works fairly well, and there are few misissuances. There are not a lack of problems, however. Extended validation certificates include information about the legal entity behind the certificate, but not much else. What a legal entity can be turns out to be quite flexible; James Burton, for example, recently obtained an EV certificate for his company “Identity Verified”. Unfortunately, users are simply not equipped to deal with the nuances of these entities, and this creates a significant vector for phishing.

Today, I will demonstrate another issue with EV certificates: colliding entity names. Specifically, this site uses an EV certificate for “Stripe, Inc”, that was legitimately issued by Comodo. However, when you hear “Stripe, Inc”, you are probably thinking of the payment processor incorporated in Delaware. Here, though, you are talking to the “Stripe, Inc” incorporated in Kentucky. This problem can also appear when dealing with different countries.

How can a user tell which one you’re talking to? Browsers hide this information at first glance, at most showing the country of incorporation. Obviously, here, both the real and fake Stripe are in the same country. With enough mouse clicks, you may be able to open a system certificate viewer, or get your browser to show you the city and state. But neither of these are helpful to a typical user, and they will likely just blindly trust the bright green indicator.


New “Quad9” DNS service blocks malicious domains for everyone

November 16, 2017 – 5:16 PM

The Global Cyber Alliance (GCA)—an organization founded by law enforcement and research organizations to help reduce cyber-crime—has partnered with IBM and Packet Clearing House to launch a free public Domain Name Service system. That system is intended to block domains associated with botnets, phishing attacks, and other malicious Internet hosts—primarily targeted at organizations that don’t run their own DNS blacklisting and whitelisting services. Called Quad9 (after the Internet Protocol address the service has obtained), the service works like any other public DNS server (such as Google’s), except that it won’t return name resolutions for sites that are identified via threat feeds the service aggregates daily.

“Anyone anywhere can use it,” said Phil Rettinger, GCA’s president and chief operating officer, in an interview with Ars. The service, he says, will be “privacy sensitive,” with no logging of the addresses making DNS requests—”we will keep only [rough] geolocation data,” he said, for the purposes of tracking the spread of requests associated with particular malicious domains. “We’re anonymizing the data, sacrificing on the side of privacy.”

Intelligence on malicious domains comes from 19 threat feeds—one of which is IBM’s X-Force. Adnan Baykal, GCA’s Chief Technical Advisor, told Ars that the service pulls in these threat feeds in whatever format they are published in, and it converts them into a database that is then de-duplicated. Quad9 also generates a whitelist of domains never to block; it uses a list of the top one million requested domains. During development, Quad9 used Alexa, but now that Alexa’s top million sites list is no longer being maintained, Baykal said that GCA and its partners had to turn to an alternative source for the data—the Majestic Million daily top-million sites feed.

There’s also a “gold list”—domains that should never be blocked, such as major Internet service sites like Microsoft’s Azure cloud, Google, and Amazon Web Services. “We do realize that is hosting phishing attacks,” Baykal said. “But because this is DNS filtering, we cannot block that URL specifically. And we don’t ever want to completely block Google.”

The blocked sites, whitelist, and gold lists are then converted into a Response Policy Zone (RPZ) format before being pushed out to the clusters of DNS servers around the world maintained by Packet Clearing House via DNS zone transfers. The DNS server clusters, which are each load-balanced with dnsdist, use a mix of Unbound and PowerDNS servers to deliver responses. “We’re running two different variants behind a load balancer,” Baykal said, “so that if there’s an issue with one we can take it down, or if there’s a critical vulnerability, we can shut one down and patch it.”